This invention relates in general to methods and apparatus for analytical analysis of blood and deals more particularly with an improved erythrocyte sedimentation rate apparatus and method. The erythrocyte sedimentation rate or ESR is the rate at which erythrocytes fall to the bottom of a column of anticoagulated blood and is used in the diagnosing progress of certain pathologic conditions, especially inflammatory disorders. In the performance of this test, it is usual to collect a venous blood specimen of somewhat greater quantity than required for the test. A predetermined quantity of whole blood is transferred from the specimen container to a graduated tube, using a graduated pipette, for example. Using another graduated pipette, a predetermined quantity of anticoagulant solution is added to the whole blood. When the blood and anticoagulant have been thoroughly mixed, the graduated tube containing the mixture is supported in axially vertical position. After a predetermined period of time, usually sixty minutes, the distance from the bottom of the surface meniscus to the top of the column of red cells is recorded in millimeters. The distance through which the erythrocytes fall during one hour measured in millimeters is the ESR value.
While presently accepted test methods generally yield satisfactory results, considerable time is required to perform these tests and several pieces of laboratory equipment are used. The transferring of blood from one container to another and the handling of open containers of blood during the test procedure exposes laboratory personnel to possible infectious disease, such as hepatitis, and also introduces the risk of blood specimen contamination and spillage. The present invention is concerned with these problems.